How link and load local fonts

First you need the font file and the different font styles if it has one. And to link it you can use @font-face setting the name and the source.

@font-face {
  font-family: 'Roboto';
  src: url('./roboto-regular.woff') format('woff');
}

Then you can use it as you normally use it.

body {
  font-family: 'Roboto', sans-serif;
}